A man and a woman were witnessed "inhaling" Nitrous Oxide (nos) from balloons whilst driving on the Hog's Back A31 near Tongham before they hurled a huge bag of canisters out of the car window.

Police were called shortly after 5.30pm on Sunday (April 16) when 26-year-old Ashley Ball saw a red Fiat 500 driving "erratically" with the driver and passenger using balloons to allegedly inhale laughing gas from nos canisters.

Mr Ball then saw a huge bag of canisters hurled from the window of the car.

The carpenter from Farnham , said: "They were inhaling from the balloons whilst driving erratically, they made a left hand turn up the slip road and did a U-turn at the bollard to get back onto the same road they had just come off.

Bag of nos canisters thrown from moving car on the Hog's Back A31 (Image: Ashley Ball)

"They were in the ambulance station before turning onto the main road. As they made the U-turn, that’s when the canisters where thrown. It was a young female blonde driving and a male with brown hair [was the passenger]. Obviously I couldn't see their faces properly as they were covered with balloons.

A spokesman for Surrey Police said: "We are looking into it. No one has been arrested.

"Drug-driving is stupid, it's irresponsible and it’s downright dangerous. Anyone who does so risks killing themselves, their passengers or other innocent road users. They also risk losing their job and their licence, in addition to a criminal record, increased car insurance costs and difficulty getting into countries including the USA.”

People in Surrey can text officers on 65999 with the details of people they suspect of drink or drug-driving.

You can also contact the independent charity Crimestoppers anonymously on 0800 555 111 or report it online.www.crimestoppers-uk.org

If you know someone is driving while over the limit or after taking drugs, call 999.